Vitamin D Lowers Risk of Colon Cancer

LYON, FranceResults of a large observational study indicated a strong inverse association between levels of pre-diagnostic vitamin D and risk of colorectal cancer in western European populations, as published in the British Medical Journal (2010; Jan. 21). The study was conducted within the EPIC study, a cohort of more than 520,000 participants from 10 western European countries. A total of 1,248 cases of incident colorectal cancer, which developed after enrollment into the cohort, were matched to 1,248 controls. Vitamin D concentration (25-hydroxy-vitamin-D, 25-(OH)D) concentration showed a strong inverse linear dose-response association with risk of colorectal cancer. Compared with a pre-defined mid-level concentration of 25-(OH)D, lower levels were associated with higher colorectal cancer risk and higher concentrations associated with lower risk. In analyses by quintile of 25-(OH)D concentration, patients in the highest quintile had a 40-percent lower risk of colorectal cancer than did those in the lowest quintile. Subgroup analyses showed a strong association for colon but not rectal cancer. Greater dietary intake of calcium was associated with a lower colorectal cancer risk. Dietary vitamin D was not associated with disease risk. Findings did not vary by sex and were not altered by corrections for season or month of blood donation. Further randomized trials are needed to assess whether increases in circulating 25-(OH)D concentration can effectively decrease the risk of colorectal cancer.